Process of producing color substances



June 2, 1925;

F. K. BEZZENBERGER PROCESS OF PRODUCING COLOR SUBSTANCES 3 Sheets-Sheet 1 XQQQ GNN Original Filed June 30. 1921 lvm@ SN .NN

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F. K. BEzzENBl-:RGER

PROCESS OF PRODUCING COLOR SUBSTANCES s sheets-sheet 2 .NEQ

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' F. K. BEzzENBERGl-:R

` PROCESS OF PRODCIG vCOLOR SUBSTANCES Original Filed June 30, 1921 3 Sheets-Sheet :5

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Patented June 2, 19.25. y

' FRED K. BEZZENBERGER, 0F CLEVELAND, OHIO.

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. I Y Application led June 30, 1921, Serial No. 481,489. vRenewed October 4, 1924.

To all whom t may concern.'

" Be it known that I. Fimo K. BEzzENBER- GER, a citizen of the United States, residing at Cleveland, in the-county o f Cuyahoga and State of Ohio, have invented certain new and useful Improvements in and Relating to Processes of Producing Color Substances, of which thefollowing is a specifi cation, reference being had therein to the accompanying drawings. The invention relates to an improved process of producing color substances of va- ,rious kinds and particularly systems of related color substances of the by Norton A. Ross. y

The chief object of the invention is the provision of an improved method of determining and producing a series of color substances vof high brightness and chroma values, by admixture of which in predetermined relations can be produced a series of color substances of predetermined hue, brightness and chroma values.

kind devised Other objects of the invention, more orv less incidental or ancillary to that above stated, will be apparent from the following description. l

While the invention, in some at least of its aspects, is applicable to various kinds of color substances used in the arts, such as paints, dyes and inks, the invention has been developed in connection with the production of paints and, for purposes of explanation and illustration, will be set forth in that connection.

To insure clearness and definiteness in the description which follows, the color terminology' employed will be in accordance with the following definitions: f

l. By hue is meant the dominating wave length of the color. A

2. By value, orstrength. or intensity, or

luminosity, or brightness, is meant the Waveamplitude of the color. v v

3. By chroma or purity is meant freedom from admixture of wave lengths' other than those constituting the dominating hue of the color. f

The above mentioned system of Mr. Ross is based primarily upon the discovery, made in connection with the paint trade, that of the relatively largenumber of colors demandedby the consumer, a distinct minority -meet the major part of the demand and that the colors constituting this minority are characterized by their relative brightness while on the other hand, the

and purity,

colors making up the larger or-majority group are characterized bv comparatively lower brightness and chroma qualities. This relation between the demands of color users and the nature of the colors is apparently based on the inherent color sense of the` l average user, the brighter and purer colors beingdemanded for the majority of uses in preference to those of lower brightness and chroma' qualities.

In order to take advantage of the relation referred to, the Ross system provides a series of relatively pure bright paints adapted to meet l,the bulk of the trade demand and havv ing such characteristics, physical and chemical, as .to adapt them for intermixture in subgroups in definite proportions to produce a larger series of paints having lower brightness and purity or chroma values and responding tothe major part of the re mainder ofthe demand of the trade. WithA these two series of paints, it is necessary for the paint manufacturer to produce and for the distributor to carry in stock only those of the smaller series or group, the paints of the larger group being produced by the simple admixture of certain of the paints of the smaller group.' In order that the paints of the larger or secondary group ma vbe from the primary paints o thel smaller group as easily as possible by the Y consumer, it; is preferable that the relations produced of the colors of the two groups and of the physical and chemicalv characteristics Vof the paints of the smaller or primary group,

shall be such that each ofthe secondary paints can be produced by the admixture of a plurality of the primary paints invequal' amounts, and to make the process as simple as possible, it is preferable that each secondary paint be produced by the admixture of two of the primary paints 'in equal amounts.l

My present invention provides an improved method of determiningv and producing aseries of primary paints which shall be adapted by admixture in pairs and in equal amounts to produce a series of `known secondary paints.

In the further explanation of the invention, reference will be had to the accompanying drawings in which Figure 1 represents a chart having a. series ico - Fig. 5 shows a series of color curves such.

as are plotted with-the aid of the spectrophotometer. l

In carrying out my invention, I` Selectfrom paints in use colors which sales statistics show are demanded by the trade. In practice it is found that the trade demand is almost completelymet by eight colors supplemented by white. 4 The selection of' colors having thus been made, a-curve is then platted for each ofsaid colors with the aid of a suitably constructed and equipped spectrophotometer.v In Fig. 3 of the drawings is indicated diagrammatically, ir plan,

' an instrument of the character in question,

While in Fig. 5 is shown a series of curves such as are platted by the use of the instruments.

In Fig. 3,A is the prism of the instrument.'

i mitting a small beam of light reflected by the surface B from the source C to the prism- A. E is a telescope adapted to collect and show on agraduatedscale the colors derived from the beam of light'reflected from the surface-B. F is a surface coated with a White substance or otherwise -given a White finish to serve as a standard of comparison. G is a strong source of light. H is a second tube similar to the tube D arranged to transmit a small beam of light emanating from the source G and reflected by the surface F. K is a double, full reflecting prism, disposed at the intersection of the axes of the tubes D and I-I but covering only the upper halves of said tubes. L and M are motor driven opaque discs formed with radially tapering slots and arranged to intercept the beams of lightpassing through the slits of the tubes D and II, respectively. The discs and their motors can be adjusted toward and from the tubes D and H by suitable means, such as micrometer screws,

to vary in definite degrees the amounts of light transmitted through the tubes D and H. N; is a plate with a vertical slit inter.

posed between the prism A and the telescope 'E and, by moving'this plate laterally, any desired lines or parts of the spectra can be selected for examination While the other parts are shut out and eye confusion observer is able to directly compare similar parts of the two spectra and bythe ad 'ustment of one or the other of the discs i and ,JM can render said 'parts of the spectra equal in brightness Then, knowing from the positions and speeds of the discs L and M the relative amounts of light transl mitted from the respective sources, the brightness of the color under examination is determined for the `particular part of the spectrum under consideration. Thus, if the examination is being made of the red sections of the spectra, it is readilydetermined from thel readings of the instrument that the red light reflected by the color under examination constitutes a definite proportion of the red light reflected by the white standard. By adjustment of the plate N, different parts of the spectrum of the color. under examination can bev evaluatedand with the values thus determined a color curve such as those in Fig. 5 can beplotted. In these curves, the ordinates represent wave amplitude While the absciss represent wave lengths.v Thus, in the case of the 1m) third curve of Fig. 5, the curve shows that a surface coated with thel green color substance in question. reflects about 50% of the red, about 55% of the yellow,`about 45% of the green, about 45% of the blue 10" and about 35% of the'violet that is reflectedv of each of these colors by the standard White coated surface. In connection with the curves shown in Fig. 5, it is to be observed that the units employed are arbitrary, the 11 curves being intendedfor illustrative purposes only. i

Having, in the manner described, determined the brightness values for the one color under examination for successive lines all the Way` across the spectrum, thus securing data for the curve ofthe color, the other colors to be examined are substituted at Bone after theother, examined and their curves platted. These curves, when suitably drawn. from accurately de termined values, give the true compositions of the light reflected by surfaces coated with the corresponding color "substances asv compared with the commor. standard, and consequently truly represent the relative color values as seen by the eye. In Fig. 5 of the drawing, the first curve representing a4 yellow color substance and the second curve representing a 'bluecolor substance, will 130 serve to typify color substances of the pri` mary group of the system, while the third curve representing a en color substance may be taken to typi y color substances of the secondary-group. The color substance represented by. the third curve is such as would be secured by mixing the yellow and blue color substances shown by the first and second curves, in equal amounts, neglecting effects due to thenature of the vehicles, particle size of the pigments, etc., these effects ordinarily being slight;

The curves of the character in question having been drawn for all of the colors which are to be represented in the complete system of paints to be reproduced, the next step in the procedure is the inspection of the curves.- On comparison of the curves,

it is found that they can` be divided into two more or less well defined groups. one group, each curve is characterized by relatively large wave amplitude values in .one part or in relatively few parts of the spectrum, thus indicating colors of relatively great brightness and purity, while 1n the other group each curve is characterized by lesser `wave amplitude values with said values about equal in a number of parts of the spectrum, thus indicating colors of lowy er brightness and chroma values than those of the first group. Furthermore, if as many as seventy-tive or eighty colors representing the demands of the trade are undei examination, it will be found that the first group of curves is relatively small in number in i comparison with the second group. In a word, the small group of curves is found to correspond to the relatively small number of colors which are shown by'experience to respond to the major part of the trade demand, while .the larger group of curves corresponds to thelai'ger group of colors which are shown by experience to respond to the remainder, or substantially all of the remainder, ot the tradedemand.

The curves having thus been divided into two groups corresponding to the primary and secondary color substances ofthe Ross system, the next step ,isl to determine Vthe nature of the colors which it will be necessary to combine in pairs and in equal quantities to produce the respective colors of the secondary group. A person `familiar with the laws of colorv synthesis, on comparing the curves of the two groups, will,

without any great diiiiculty, be able to de-A termine what colors of the general character of those in the primary group are required to produce by combining, in pairs and in equal quantities, the respective colors of the secondary group. In this manner, it is possible to determine the number of different primary colors that will be required for the production of the secondary colors in the manner stated.

Inl

the twenty points.

The next step in the procedure is the vmathematical determination of the exact.

data for the curves ot' these undetermined primary colors. n To do this a suitable number of points, say twenty points as indicated in Fig. 5, are taken on the base lines of spending to oneof the undetermined curves.

If we designate the known ordinate values of the secondary color curves by suitable symbols corresponding to one of the second-y ary color curves, then,`bearing in mind that the rimary colors are to be vcombined in equa quantities and having determined from a knowledge of the laws of color4 synthesis the primary colors which are com#C the curves of the secondary colors and for A each curve the ordinates corresponding to binable to produce the secondary colors, we i can writevfor each of the twenty points of each ot the unknown primary 'color curves an equation in this form For each ofthe twenty pointsv there will be as many equations as there aresecond-A ary colors and these equations for any one point will readily be grouped into simultaneous equations for solution as such. In this manner, the values of the wave amplitude ordinates for the respective primary color curves are determined for the first of Then y corresponding computations .are carried out for eacli of the remainingtwenty points. The values derived from. these computations will be plotted as new curves which will be mathematically descrip-tive of the primary colors capable of combination in pairs and in equal quantities to produce the secondary colors.- AHaving plotted these mathematically determined primary color curves, it will be found that inmost cases, the mathematical-- ly determined curve corresponds more or less closely'to one of the primary color curves plotted by the use ot' the spectrophotometer. The next step in the procedure is the production of primary paints corresponding to the mathematically determined color curves. For thispurpose, we require the curvesof all common pigments which are'mutually chemically inactive, Y ble to deleterious chemical reaction, and otherwise suited to the purpose.` From these latter curves and the curves of the mathematically determined primary colors, it is possible by inspectionand by simple proportionate addition of ordinates, to deter- `mine approximately the relative quantities or at least not susceptied together to produce the desired primary colors. It is to be understood that white is included in the primary color group.

Having determined the color pigments and the amounts thereof required for the desired primary paints, said pigments are compounded With suitable vehicles composed of oils, driers and the like, and any other suitable ingredients, of such a nature that the primary paints which must be mixed in pairs to produce the various secondary paints shallbe capable of such admixture Without deleterious chemical reaction or any other effect that would objectionably modify the Working, drying or Wearing qualities of the substances mixed. lVhere substantially the same vehicle can be'used for all the primary paints, these conditions are obviously met in -the simplest Way, but, as will be obvious to those skilled in the production of paints, it is possible to secure substantially as good results by the use of differentv duce a paintof which the pigment will not settle to some extent on standingbut, as is Well known, it is possible tol/prevent caking, hardening or separating of the igment so that by thoroughly stirrin/g or oXing, all of the ingredients Will be lremixed in the desired proportions.

Having prepared the/ primary paints in accordance with the foregoing requirements,

said paints are then examined with the spectrophotometer and their curves drawn and checked with the mathematically determined curves of the primar/y color substances.

Proceeding in the above manner, a series of primary color'j substances is produced whichin turn are l/capable of producing, by admixture in equal quantities in pairs, the desired series of secondary color substances.

While, in carrying out my process, I prefer to plot the yvave amplitude-Wave length curves representing the color substances of low brightness" and chroma values andthe color substances of high brightness and chroma values and also the common pigments, because such graphic representations facilitate/the procedure, it is to be `understood that the process can if desired be carried out Without lotting the curves. That is to say, the brightness values, measured or computed for the dilerent lines of the spectrum of a color substance canbe directly compared with the corresponding brightness values of another color substance Without the use of the graphic representations of the values.

In the distribution of paints ofthe character above described, the dealer is provided with' the color 'charts indicated in Figs. 1 and 2 of the drawinvs.

As will be understood, the paints represented by the small group of panels are the ones produced by the manufacturer and carried in stock by the dealer, while the paints represented by the larger group of color panels are produced by mixing the proper primary paints. To facilitate the production of the secondary paints by the user or the distributor, each of the primary paints is designated by some symbol other than the name of its color, preferably by numbers as indicated in Fig. 1 of the drawing. Then each of the secondary colors is designated by a legend madeup of the numbers of the primary paints which when mixed in equal proportions produce said secondary paint.

Thus, if a purchaser selects paints from the secondary group, it is a very simple matter for the dealer to determine from the f and also a very simple matterfor the pur-V Chaser on reference to the charts to mix the primary paints for the production of the secondary paints when the latter are required for use.

From the foregoing description, it will be seen that my invention provides a method which, by quantitive evaluation of color quantities, is adapted to determine the compositions of a series of desired color substances capable of mixture in a given Way to produce another series of known color substances having the general character of the secondary colors of the Ross system. And this method, being based on the physical measurement of the fundamental color qualities, is accurate and dependable. Furthermore, an operator familiar with the `method and the spectrophotometer employed can proceed rapidly and systematicall through the several steps ofthe process wit i practically no recourse to time-consuming determinations of composition bytrial.

It will be understood that my process is I' not limited in its application to the production of paints nor to the production of groups of color substances related in the specific manner above described, but that the scope. ofthe invention is 'indicated by the appended claims. v

What I claim as my invention is:

1. The process of makingv color substances for use in the arts which comprises making spectrophotometric measurements of rthe brightness values of each color to be produced at a series of points throughout its required for use.

spectrum, plotting a curve of the wave amplitude-wave length values thus determined for each of the colors, dividing said curves into two groups one of which comprises the colors having lower brightness and chroma values, than the colors of the other'group, determining according to the laws of color synthesis the number and general character of primary colors of comparatively high brightness and chromanzalues that will be required to produce when mixed in certain sub-groups in uniform proportions the said colors having low brightness and chroma values, computing the brightness values for a series of points in the waveamplitudewave length curves of said primary colors by simultaneous equations having' unknown values representingbrightness values of the primary color curves and known values representing the brightnessvalues measured as aforesaid, plotting the wave amplitudewave length curves of the primary colors fwiththe values thus computed, plotting-the wave amplitude-,wave length curves of the common pigments capable of mixing without deleterious chemical reaction, determining the compositions of the primary color substances by comparison* of the curves thereof and the curves of said pigments, pre-`- s paring color substances having the compositions thus determined, and thereafter mixing together said primary color substances in themanner specified as the color substances of the lower brightness and chroma values are 2. The steps 1n a process of making color substances for use in the arts which consist in making spectrophotometric measurements of the brightness values of each color to be produced at a series of points throughout its spectrum, plotting a curve of the wave amplitude-wave length values thus determined for reach of the colors, dividing said curves into two groups oneof which comprises the colors havingv the lower brightness and chroma values, than the colors of the other group determining according to the laws of color synthesis the number and general character of primary colors of comparatively high brightness and chroma values that will be required to produce when mixed in certain'fsub-groups in uniform proportions the said colors having low brightness and chroma values, computing the brightness values for a series of points in the wave amplitude-wave length curves of said primary colors by simultaneous equations having unknown values representing brightness values of the primary color curves and known values representing the brightness values measured as aforesaid, plotting the wave amplitude-wave length curves ofthe primary ,colors with the values thus computed, plotting the wave amplitude-wave length curves of theV common pigments capable of mixing without deleterious chemical reaction, determining the` compositions of the primary' color substances by comparison of the curvesthe'reof and the curves of said pigments, and preparing color substances having the compositions thus determined.

y 3. The process of making color substances of low brightness and chroma values for use puting the brightness values for a series of' points in the wave amplitude-wave length curves of said high value colors by simull i taneous equations having unknown values representingbrightness values of the high value color curves and known values re re-` senting the brightness values'measure as aforesaid, plotting the wave amplitude- 'i vwave length curves of the high value colors with the values thus computed, plottin the wave amplitude-wave length curves o the common pigments capable of mixing with, out deleterious chemical reaction, determining the compositions of the high value color substances by comparison of the curves ,thereof and the curves of said pigments, preparing color substances having the compositions thus determined, and thereafter mixing together said high value color substances in the manner specified as `the' color substances of low brightness and chroma values are required for-use;

4. The process of making color substances 'I for use in the arts which comprises making spectrophotometric' measurements of the brightness values of each color to be produced at a series of points throughout its I spectrum, dividing ysaid colors into two groups one of which comprises the colors n.5,

having lower brightness and chroma values than the colors of the other group, deter'- mining according to the laws of color synthesis the number and general character of primary colors of lcomparatively high ybrightness and chroma values that would be required to produce when mixed in certain sub-groups in uniform proportions said colors having low brightness and chromal values, computing the brightness values for a series of lines in the spectra of said primary colors by simultaneous equations having unknown valuesA representing the brightness values of the primary colors and known values representing the bri htness values measured as aforesaid, determining the joomsubstances for use in the arts which consist color substances in t e manner s eciied as,

the color substances of the lower rightness and chroma -values `are required for use.

5.' The steps in a process of making color in making spectrophotometric measurements of the brightness values of leach color to be produced at a series of points throughout its spectrum, dividing. saidv colors into two Groups one of which comprises the colors having lower brightness and chroma values than the colors of the other group, determining according to the laws of color synthesis thenumber and general character of primary colors of comparatively high brightness and chroma values that would be required to produce when mixed in certain subgroups in uniform proportions said colors having low brightness and chroma values, computing the brightness values for a series of lines in the spectra ofsaid primary colors by simultaneous equations having unknown values representing the brightness values of the primary colors and known values representing the brightness values measured as aforesaid, determining the compositions` of the primary color substances by comparison of their brightness values computed vas aforesaid with the corresponding brightness values of the common known pigments capable of mixing without deleterious chemical reaction, and preparing colorsubstanccs having the compositions thus determined.

6. The process of making color substances of low brightness and chroma -values for use in the `arts which comprises making spectrophotometric measurements of each of such colors to be produced at a series of4 points throughout its spectrum7 determining according to the laws of color synthesis the number of colors of highbrightness andv chroma values that will be required to produce when mixed incertain subgroups in uniform proportions the colors represented by said brightness values, computing the brightness values for a series of lines in the-spectra of said high value colors hy 'simultaneous' equations having unknown values representing the brightness values of said high value colois and 'knownvalues representing the brightness values measured as aforesaid, determining the compositions of the said high lvalue color substancesiby comparison of the brightness values com'- Aputed as aforesaid with the corresponding brightness values of the common pigments capable of mixing without deleterious cheniical. reaction, preparing color substances having the compositions thus determined, and thereafter mixing together said high Value color substances in the .manner speci- 7 fied as the color substances of low brightness and chroma values are required for use.

7. The process of making color substances for use in the arts which comprises determining the brightness of each color to be produced at several points in its spectrum; dividing said colors into two groups one of whichv comprises the colors having lower brightness and chroma values than the colors of theother group; determinin according 8 to the laws of color synthesis t e primary colors of comparatively high brightness and chroma values that would be required to produce when mixed in certain sub-groups in uniform proportions said colors having 8i low brightness and chroma values; determining mathematically the brightness values at corresponding points in the spectrum requisite for said primary colorsl to produce the aforesaid colors of lower .rightness and chroma values; determining the compositions of the` primary color substances by -comparison of their brightness values determined as aforesaid with the corresponding brightness values of. 9

-mary colors of comparatively high bright- -ness and chroma values that would be re- -quired to produce when mixed in certain sub-groups in uniform proportions said colors having low or moderate brightness 1 and chroma values; computing mathematically the brightness values ofsaid primary colors corresponding to the spectro-pliotometric determinations of the colors to be produced; determining the-compositions of 1 the primary color substances by comparison of their rightness values computed as aforesaid with the corresponding brightness values of the common known pigments -cacal reaction; and preparing color substances having the compositions thus determined.

In testimony whereof, I hereunto affix my signature.

FRED K. BEZZENBERGER.

pable of mixing without deleterious chemil L5 my@ Q Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,540,098, granted June 2, 1925, upon the application of Fred K. Bezzenberger, .of Cleveland, Ohio, for an improvement in Processes of Producing Color Substances, errors appear in the Jrinted specification requiring correction as follows: Page 2, line 18, for the Word eight read eighty; lines 2l and 27, nfor the Word platted read plotted; page 4, line 103, for the word quantities read qualities; and that the said Letters Patent should be read with these corrections therein that the. same may conform to the record of the case in the Patent Office. l Signedand sealed this 7th day 0f July, A. D. 1925.

[SEAL] ,'WM. A. KINNAN,

, l Acting Uammz'ssz'onfer of Patents. 

